What HDZero Costs

Same frame class, same pack, same Gemfan 1219 3-blade props. The only meaningful difference between these two builds is the video system and motor spec — and the digital build gives up a third of its flight time for the picture.

The current delta is bigger than the weight delta alone predicts — the HDZero VTX draws its own supply on top of what the heavier build asks from the motors. Full write-up: HDZero vs analog — what video weight costs in flight time.

Air65 Analog — Full Record

Onboard current sensor reads about 20% cold out of the box — raw OSD showed 217 mAh for a run that delivered roughly 270. Correction factor 1.24, anchored to a full discharge. Slow cruise pace throughout. Raw record: air65-analog-vci0702-30k.json. Pending: hover run, repeat cruise, rest-voltage logging, top speed in calm air.

Mobula6 2024 HDZero — Full Record

Opposite sensor problem to the Air65 — this one reads about 25% hot. Raw OSD claimed 340 mAh from a 300 mAh pack; correction factor 0.79. OSD also showed 4.15 V at plug-in against a true 4.35 (connector drop plus ADC offset). Slow cruise pace. Raw record: mobula6-2024-hdzero-se0702-28k.json. Pending: hover run, repeat cruise, rest-voltage logging, top speed in calm air. Build write-up: 65mm SE0702 + Gemfan 1219 build guide.

TreeTopper 75 Analog — Full Record Provisional

Uncalibrated sensor, uncontrolled runs. The mAh figures in this section are raw OSD readings, and Avg A and mAh/min are worked out from them and the stopwatch time. None has been corrected, because there is nothing to correct it against — this build has never been flown to a full discharge, so it has no anchor and no correction factor. The two 65mm builds read 20% cold and 25% hot out of the box; assume an error of that order here until it is measured. All three runs were uncontrolled: runs 1 and 2 started undercharged with mismatched cutoffs, and every run used a freestyle throttle profile that does not repeat. The runs are therefore not a pack A/B comparison, and this build feeds no calculator estimate.

Run 1 started at 4.10 V against a 4.35 V LiHV full charge and pulled roughly 60% of rated capacity; run 2 started at 4.25 V, ran to a deeper cutoff, and pulled roughly 68%. Run 3 started from a full 4.35 V on a weBLEEDfpv 450, indoors at 79 °F, landed at 3.40 V, and its raw count is 97% of rated capacity — the record advises a puff check on that pack. None is a discharge curve. Durations and weights carry no sensor caveat and stand on their own. Raw record: treetopper75-analog-0802-32500k.json. Pending: current sensor calibration against a full-discharge anchor, matched-condition A/B (same charge state, same cutoff, same profile), n=3 per pack, a controlled cruise run, rest-voltage logging.

Fractal 75 Analog — Full Record Provisional

Uncalibrated sensor, uncontrolled run. The mAh figure in this section is the raw OSD reading; Avg A and mAh/min are worked out from it and the stopwatch time, so all three carry the same uncorrected sensor error. This build has never been flown to a full discharge, so it has no anchor and no correction factor. The 65mm sensors read 20% cold and 25% hot out of the box; nothing bounds this one. One freestyle run, on a throttle profile that does not repeat. It feeds no calculator estimate.

Full 4.35 V LiHV start, landed at 3.40 V under load, indoors at 79 °F. The raw OSD count is 87% of rated capacity. Durations and weights carry no sensor caveat. Raw record: fractal75-analog-rcinpower0802-25k.json. Pending: current sensor calibration against a full-discharge anchor, n=3 matched-condition runs, a controlled cruise run, rest-voltage logging.

Cockroach 75 HDZero — Full Record Provisional

Miscalibrated sensor, uncontrolled runs. On run 2 this build's current sensor read 542 mAh on a 450 mAh pack and an 18 A peak, so run 2's current and mAh readings were discarded rather than published raw; run 1's were never captured. The record has no current or mAh figure for either run. Both runs were freestyle on a throttle profile that does not repeat. Durations and weights stand on their own; this build feeds no calculator estimate.

Both runs started from a full 4.35 V LiHV charge, indoors at 79 °F. The record gives a 3.40 V landing under load for both, but run 1's notes also say its cutoff and mAh were not captured, so that landing figure is unconfirmed. Raw record: cockroach75-hdzero-champion0802-28k.json. Pending: fix current_meter_scale before any current data is kept, then a full-discharge anchor; n=3 matched-condition runs; a controlled cruise run; rest-voltage logging; a PID tune for the start-of-pack wobble.

Methodology

Whoop-scale current sensors are not trustworthy out of the box — one 65mm build read 20% cold, the other 25% hot. The policy is that every current and mAh figure gets corrected against a full-discharge anchor before it is published.

Three builds on this page do not meet that bar yet. None of the 75mm builds has been flown to a full discharge, so none has an anchor, a correction factor, or an uncertainty figure. The choice there is publish raw or withhold, and withholding is the worse of the two — a missing build teaches nothing, while a flagged one still carries usable durations and weights. So they are published raw, except where the record judges a sensor grossly miscalibrated (the Cockroach 75, which read 542 mAh on a 450 mAh pack and an 18 A peak on run 2), and those figures are dropped instead. Every uncorrected figure is marked Provisional on the row, rendered in amber with a "raw, uncorrected" marker on the cell, and spelled out in full under the build's own record. Provisional builds are excluded from cross-build comparisons and never feed a calculator estimate. They lose the flag when the sensor is calibrated and the runs are re-flown controlled — not before.

When your inputs in the calculator match one of the calibrated builds, it swaps its estimate for the measured number. Provisional builds are not wired in — none of the 75mm builds changes an estimate. Everything on this page is reproducible from the raw JSON in data/bench/. More builds get added as they cross the bench.